This invention relates to an apparatus for determining the mass of an object in a zero gravity environment. In zero gravity environments, such as in space, the mass or weight of an object cannot be measured with a conventional scales. The U.S. Pat. No. to Dryden, 3,379,974, discloses a system for determining momentum and velocity of particles in space. Other systems are known for providing information regarding particles in zero gravity environments which require the use of a powered shaker.